Whereas decision-making groups can benefit from pooling members′ unique knowledge, they often do not benefit because information that is held by only one member is omitted from discussion (Stasser, Taylor, & Hanna, 1986b). However, if members are assigned expert roles, they may be able to implement a cognitive division of labor that promotes the sampling and use of members′ unique knowledge. Participants in this study read a homicide mystery and then met in three-person groups to discuss the case and select the guilty suspect. A group collectively had all the clues, but each member read a version of the mystery that contained only a subset of the clues that were critical to identifying the correct suspect. Groups were more likely to select the correct suspect and mentioned more of the unshared clues when members were told who in the group had additional information about each suspect. However, simply forewarning individual members that they would receive more information about a specific suspect did not have these beneficial effects. These results suggest that adequate collective sampling of unshared information depends on coordinated information processing which is based on members mutually recognizing each other′s responsibility for specific domains of information.